Groove-finishing apparatus



T. MARREN 2,398,022

GROOVE FINISHING MACHINE 5 shees-sheet 1 A A m Nm, O S .w N T i @Mmmm x.EW

April 9, 1946. T MARRE 2,398,022

GROOVE-FINISHING APPARATUS Filed July 22, 1944 5 sheets-sheet 2 a, 32 3252 Z/a INVENTORv Thomsfrren BY l ,/7

ATTORNEYS April 9, 1946. vT` MARREN 2,398,022

GROOVE-FINI SHING APPARATUS Filed July 22, 1944 5 sheets-Sheet 3 lATTORNEYS T/mm as M02 'rch' Apm 9, 19216.

T. MARREN GROOVE-FINISHING APPARATUS Filed'July 22, 1944 5 sheets-sheet4 I Rg. /2

April 9, 1946. T, MARREN GROOVE-FINISHING APPARATUS Filed July 22, 19445 Sheets-.Sheet 5 y INVENTOR N /omzs Marre/7 JM/MW T ATTORNEYS PatentedApr. 9, 1946 UNITED STATES PATENT OFFICEA GROOVE-FINISI-IING APPARATUSThomas Marren, Stamford, Conn.

Application July 22, 1944, Serial No. 546,176

(Cl. Eil-58) 23 Claims.

This invention relates to apparatus for finishing grooved surfaces ofmachine parts and the like, and more particularly to a machine forPrecision grinding, lapping and polishing the tracks or grooves ofproduction parts such as ball bearing races. v

In the manufacture of inner rings or races for ball bearing assemblies,it is common practice to turn each ring roughly to form, as on a screwmachine or the like, after which the rings are hardened and groundexcept for the grooves, preparatory to finishing the critical surfacesof the latter.

The finishing oi the grooves is in many cases done partly by hand, theprocedure being to mount a number of rings on a mandrel which may berotated at high speed, and to apply a grinding or lapping stone to thegrooves in the rings one at a time, holding the stone with a uniformpressure against the surface of the groove, and moving the stone so asto uniformly traverse and clean out the rough area. This method whendone skillfully is usually precise enough for theV final lapping andpolishing of the grooves but is slow and costly, and may not be used forthe heavier grinding operations. For, if comparatively large amounts ofstock were to be removed from the groove, as by a coarser grindingoperation, the groove would become out-of-ground due to theimpossibility of producing precise movements and pressures by hand onthe grinding stones.

Efforts have been made heretofore to use machinery for grinding andpolishing the groove in cach ring, but diiculties were encountered inmaintaining the proper pressures and movements of the stones, and it wasfound that the grooves became egg-shaped as a result. Moreover, with themachinery employed, only one ring at a time was Worked on, and the timeconsumed in the operation was therefore still considerable and costly. l

It is an object of this invention to provide a groove-grinding andfinishing machine which obviates the above difficulties.

This is accomplished by the provision of a mechanism for applying, witha predetermined oscillatory curvilinear motion, grinding or lappingmeans under uniform pressures to movably mounted workpieces, as forinstance bearing rings, in a manner that the surfaces of the groovesthereof are uniformly finished.

In the form of this mechanism, illustrated herein as exemplary of theinvention, a plurality of bearing rings to be finished are mounted on amandrel which issupported at both ends and turned preferably at highspeed. A plurality of holders are arranged in tandem to slidably carryfinishing elements, the holders being individually pivotally mounted ona carriage having an operative position with respect tothe mandrel, sothat the finishing elements of the holders may engage and transverselysweep the grooves in the rings along an arc having a centersubstantially coincidental with the lcenter of curvature of the grooves.The holders are interconnected, and automatically driven to oscillateabout their pivots in unison, causing all the finishing elementssimultaneously laterally to traverse along these predetermined arcs thegrooved surfaces of the respectively engaged rings. Means are preferablyprovided for applying uniform individual pressures to the elementsduring their oscillating movements, and in the illustrated form of theinvention this means is exemplified by a flat tubular inflatable memberof rubber or other flexible material engaging force-transmitting linksor couplings connected with the slidable finishing elements and soarranged that they may apply substantially equal and uniform workingpressures to the latter.v These applied pressures cause all the elementsto press uniformly and with equal force against the surfaces oftheygrooves, and this together with the arcuately correct travel of theworking surfacesv of the elementsv controls uniformly the amount ofmaterial 'removed from the rings during the finishing operation. v

In the form shown the construction is such that, when the rings on themandrel have been finished, the machine housing may be swung open on aparting line, together With a hinged cap on one of the bearing blocksfor the mandrel, so that the latter may be quickly and convenientlylifted out and replaced by another mandrel having'unfinished ringspreviously arranged thereon. Thus high production is possible, due tothe simultaneous finishing of all the rings on a mandrel in oneoperation, and the provision of means for quickly replacing mandrels.

By the above arrangement, the arcuate movements of the Working surfacesof the elements, and the equality and uniformity of the pressures ofSame against all the rings simultaneously provide a high degree 0faccuracy in the finished grooves, so that few, if any, rings arerejected.

The machine housing has a second parting line to provide access to thefinishing elements, the mountings for which permit quick replacement ofbroken or worn abrasive elements to be made. A Window in the housingpermits observing the condition and setting of the elements duringrunning of the machine, so that improperly finished workpieces may beheld to a minimum.

By the provision of the iniiatable bag, constant easily controlledpressures are maintained at all times on the elements even when thesewear away unevenly, since a considerable displacement of the bag at anyone point is possible Without materially affecting adjacent portions.

The finishing elements carried by the holders may be sufiicientlycoarse, and the iiuid pressure transmitted thereto suiiiciently great toenable coarse grinding of the grooves. Or, by changing to lesserpressures and finer abrasive elements, accurate lapping and polishingoperations may be carried out.

Provision is made for adjusting the location of the axis of oscillationof the mounting means for the finishing elements, so that finishingoperations on race grooves of either small or large radii, or small orlarge diameter bearing rings may be carried out.

The transmission of pressure from the iniiatable bag to the finishingelements is preferably carried out byV individual link assemblies, eachcomprising a slide and a pivoting arm. The construction is such that,when the finishing elements are oscillating, resulting small periodicincreases in the pressure exerted by the bag are compensated by slight`diminutions of pressure due to the angularity of the pivoting arms. .Asa result a substantially constant pressure is maintained at all timesbetween the working surfaces of the finishing elements and the groovesof the workpieces.

A separable driving connection is provided between the pivotally mountedpressure transmitting arms and the finishing elements, and means areprovided for aligning the arms when the housing is opened along theparting line provided to give access to the finishing elements, so thatwhen the housing is again closed the matching parts of the arms andelements will be aligned for meshing.

Another feature of the invention is the provision of adjustable meansfor taking upwear in the mountings of the elements so that the positionsof the latter may be accurately held at all times, providing `foruniform accuracy in the finishing f the rings.

In an illustrated modification, mounting means or holders are providedfor carrying a plurality of elements to be applied to the individualbearing rings, thus minimizing the wearing of each element and alsoproviding for a quicker finishing of the grooves thereof.

Other features and advantages will hereinafter appear.

In the accompanying drawings- Figure 1 is a longitudinal verticalsectional-V view through the machine of this invention.

Fig. 2 is a transverse vertical section taken on the line 2-2 of Fig. l.u

Fig. 3 is a part-plan, part-sectional view on line 3-3 of Fig. 1.

Fig. 4 is a front elevation of the machine.

Fig. 5 is a fragmentary right end elevation of the machine, showing thesplit bearing Vfor the mandrel.

Fig. 6 is a view similar to Fig. 5, but showing the upper half of themachine swung backward and the split bearing for the mandrel separatedto permit removal of the latter.l

Fig. '1 is a left end elevation of the machine showing the upper half ofthe machine swung backward as in Fig. 6, for removing the mandrelcarrying the bearing rings.

Fig. 8 is a transverse sectional view similar to Fig. 2, but partly inelevation and showing the upper portion of the machine housing swungbackward to permit access to the finishing elements.

Fig. 9 is a fragmentary sectional view similar to Fig. 1, but showingthe finishing elements and holders in inclined position.

Fig. 10 is a vview similar to Fig. 9, but showing the machine adjustedfor finishing slightly larger sized bearing rings.

Fig. 11 is a view similar to Figs. 9 and 10, but showing the machineadjusted for finishing still larger sized bearing rings.

Fig. 12 is a sectional view showing a modified form of holder, carryinga pair of finishing elements.

As shown in Figs. 1 and `2, the machine embodying this inventioncomprises an elongate stationary Abase 20 which may be of cast iron orother suitable material, having front and rear walls 20a, a left endwall 20h and a right end wall 20c. Mounted within the walls 20a, 20h and20c of the base is an upstanding housing 2|, the front and rear walls 2|a of which extend respectively inside the walls 20a and the left endwall 2lb of which extends inside the end wall 20h. The right end wall2|c of the housing is located directly over the end wall 20c of the baseand substantially in alignment therewith.

The end wall 20h of the base has rotatably mounted therein a bushing 22having a cylindrical recess 23 and square counterbore for receiving thesquare end 24a of a mandrel 24 carrying a plurality of bearing rings 25.The other end 24b of the mandrel is carried in a split bearing block 26forming part of the end wall 20c of the base. As shown in Fig. l, therings 25 are mounted with spacing collars 27 between them so that theyare uniformly spaced on the mandrel, the latter being provided withthreads and a nut 28 which when tightened secures the rings 25 andcollars 21 tightly against a shoulder 29 on the mandrel.

The bushing 22 is provided with a. drive pulley 30 by means of which itmay be rotated, togetherwith the mandrel 24 and bearing rings 25,through connection with a driving motor not shown.

According to the present invention a mechanism is provided within thehousing 2| for mounting finishing elements so that they may be made tolaterally sweep or traverse with a predetermined periodic motion andwith uniform pressure the grooved surfaces of the bearing rings 25 forprecisely finishing said surfaces.

As shown, a plurality of tubular holders 3| having angularly extendinglegs 3|a are mounted by means of the latter on pivot screws 32 threadedinto the front and rear walls of the housing 2|. The holders 3| areindividually connected to a driving link 33 so that they may be made tooscillate in unison. Each of the holders 3| slidably carries a sleeve34, Fig. 2, in which is frictionally mounted a finishing element 35, thelower portions of the sleeves being split, as shown at 3|b, Fig. 8, andbiased inwardly for this purpose. The elements 35 may be of abrasivestone or the like. The top ends of the sleeves 34 have rigidly attachedthereto caps 36 by means of which pressure is applied to the finishingelements 35.

By the provision of the pivotally mounted holders 3|, the finishingelements 35 may be caused to pivot aboutV a point which exactlycoincides with the center of curvature of the grooves in the bearingrings 25, means being provided for this purpose for adjustably raisingor lowering the housing 2l carrying the pivot screws 32. An angularposition of the holders 3l and elements 35 illustrating this pivotalmovement is shown in Fig. 10. For the purpose of vertically adjustablypositioning the housing 2 I, referring to Fig. 1, the front and rearwalls Zia of the housing are provided With pairs of depending lugs 2Idhaving camming surfaces on their under sides engaging cams 31a of a camframe 31 slidably carried on tracks 38 and adjustable by means of ascrew 39 passing through the end wall 2Ilb of the base and having aknurled handwheel 43. Preferably the depending lugs 2Id are providedwith downwardly extending lips 2le for guiding them on the cams 31a. Toprovide for vertically accurate movement of the housing 2| the front andrear walls 2 la thereof have apertured lugs 4l for sliding on guideposts 42 which are rigidly mounted on the sub-base S.

By this construction it is possible to adjust the heights of the pivotscrews 32 to suit the various sizes of bearing rings placed in themachine. Referring to Fig. 9, the housing 2l is shown in a low positionwherein the pivot screws 32 are aligned with the centers of the radii ofcomparatively small bearing rings a. In Fig. l0 the housing 2| is shownin an intermediate position to accommodate the machine for the mediumsized bearing rings 2517, :and in Fig. 11 the housing is shown in anelevated position to accommodate the machine for large sized rings 25e,these various positions being attained by turning of the knurled wheelto operate the camming frame 3l.

For the purpose of oscillating the holders 3S and finishing elements 35carried thereby, a cam drive is provided from the pulley 3D to thedriving link 33. As shown in Fig. l, a worm 43 is mounted to rotate withthe pulley 33 and engage a worm gear 44 mounted on a spindle 45 carriedin brackets 46 integral with the end wall 23h of the base. Also, mountedon the spindle is a heartshaped cam 41 engaged by a roller 43 carried byone end of a pivotally mounted arm 49 the other end of which carries aroller 50 extending into a goose neck 5l on the end of the driving link33, the sliding engagement provided by the goose neck 5I permittingvertical adjustment of the housing 2| by the cam frame 3l. As shown inFig. 1, the arm 49 pivots on one of the brackets 43 carried by the wall20h of the base, and for the purpose of maintaining the roller 48 inengagement with the cam 41 a coil spring 52 is connected from the wall20D to the arm.

According to the present invention link means are provided forindividually applying pressures to the oscillating caps 36 and sleeves34 to be transmitted to the finishing elements 35 in such a manner thatthe latter will exert substantially equal and uniform pressures on thegrooved surfaces of the bearing rings 25.

As shown in Figs. 1 and 2, the housing 2i carriesa plurality of verticalslides 53 mounted by pairs of shouldered screws 54 extending throughslots 55 in the rear Wall 2| a of the housing. At its lower end eachslide 53 pivotally carries a pressure-transmitting or connecting arm 53eX- tending upwardly along the inner side of the slide and having alaterally extending convexed portion 56a engaging a cylindrical slot inthe cap 35. The slides 53 also have laterally extending arms 53aengaging the underside of an inflatable tubular bag 51 provided with anipple connection 58. According to this construction, when the bag 57 isinflated its underside will bear against the arms 53a of the slides 53,providing a downward pressure thereon. This pressure is transmittedtothe connecting arms 53 and thence to the caps 36 and sleeves 34. As aresult, a pressure is applied to the finishing elements S5, causingtheir lower ends to bear against the grooves of the bearing rings 25. Itwill be noted, referring to Fig. l0, that the pressure transmitted fromthe slides 53 to the finishing elements 35 is variable due to theangularity of connections at the ends of the connecting arms 55. Whenthe holders are in their vertical position, as shown in Fig. l, thepressure applied to the slides 53 will be transmitted substantiallywithout change to the finishing elements 35. When the holders 3l are `inan angular position, as shown in Fig. 10, pressure Iapplied to theslides 53 will be only partially transmitted to the finishing elementsdue to a horizontal component of pressure being present. However, forthe angular position of Fig. 10 the slides 53 arerelevated slightly, ascompared to the Fig. l position, so that the bag 5l is compressed. Thisincreases the pressure exerted by the bag on the slide, and as a resulta compensating effect is had whereby the resultant pressure exerted bythe finishing elements on the bearing rings may be maintainedsubstantially uniform.

ft will be noted that the inflatable bag 5l thereby causes pressures tobe applied individually to the finishing elements 35, these pressuresbeing all equal and substantially uniform throughout the oscillatingmovement of the elements. As a result, the amount of material removedfrom each of the grooves of the bearing rings 25 will be substantiallyequal, providing the finishing elements S5 are all of equal coarsenessor fineness. Even if one or several of the finishing elements were towear slightly more rapidly than the others, the difference in thepositions of the sleeves 34, connecting arms 56, and slides 53 would notcause appreciable differences in the pressures on the rings 25, sincethe resilience of the lower wall of the bag 5l is able to accommodatedifferent positions of the slide, and since the hydraulic pressure atall points on the lower wall of the bag is substantially equalregardless of slight Variations of position. Close control of thefinishing of the bearing grooves is possible due to the ease with whichthe pressures of the elements may be controlled, by controlling thehydraulic pressure in the bag 5l, which may be done by any of numerouswell-known devices,

For certain conditions it may be desirable to clean out the sides of thegrooves more than the bottom, or vice-versa, and the adjustment forraising or lowering the housing 2l may be utilized for this purpose.For, if the pivot points of the holders 3i are located either above orbelow the centers of curvature of the grooves in the races, the materialremoved from the groove will vary accordingly. As an example, if a groupof rings s to be finished in which the grooves are somewhat egg-shaped,this condition may be corrected in the finishing by properly locatingthe pivot points about which the nishing elements swing.

When the stones 35 become worn, their usefulness may be extended byproviding shims 35a under the caps 36, as shown in Fig. 2, and thecondition of the stones during operation of the machine ma'y be observedthrough a window Zig, Fig. 4, provided in the front wall 2 la of thehousing.

The machine may be shut ofi after a predetermined number of oscillatingmovements of the finishing elements have been made by any suitable stopmeans.

For the purpose of providing access to the holders 3| and finishingelements 35 carried thereby, the housing 2| is made to part along ahorizontal plane 59, Figs. 1 and 2, the rear wall 21a of the housingbeing provided with a. hinge 60 at this parting line. Referring to Fig.2, a latch plate 6| and latch pin 62 are carried rigidly mounted on theportion of the housing 2| below the plane 59, the pin being engaged by alatch arm 63, mounted on the upper portion of the housing, and having anupwardly extending handle 63a. Thus, as shown in Fig. 8, the top portionof the housing 2| including the bag 5'|, slides 53 and arms 56, may beswung backward, the portions 56a of the arms becoming disengaged fromthe caps 36. The holders 3|, sleeves 34 and caps 36 are now exposed, andto remove the elements 35 it is only necessary, to lift the sleevescarrying same out of the holders. As shown in Fig. 2, the caps 36 haveapertures 36a to permit insertion of apunch for facilitating removal ofthe elements from the sleeves. Quick and convenient changes of elementsmay therefore be made as a result of this construction. For the purposeof providing for convenient re-engagement of the arms 56a and caps 36when the housing is t be closed, all of the connecting arms 56A are heldin central alignment during the open position of the housing 2| by amovable bail 64, which is mounted on arms 65 connected with the latch63, the bail extending under the end portions of the extensions 56a ofthe arms to engage same when the latch is in releasing position. Thus,when the holders 3| are centralized, the extensions 56a of the arms willbe properly positioned for engaging the caps 36 as the top of thehousing is closed. A coil spring 66 yieldably holds the latch in closedor looking position, and a pivotally mounted am 61 is provided forengaging a pin 61a to hold the latch in releasing position.

To provide for quick and convenient insertion and removal of mandrels 24carrying the bearing rings 25, the housing 2| is made to part along asecond horizontal plane 68 substantially in alignment with the axis ofthe mandrel.

Referring to Fig. 2, the rear wall 2|a of the housing is provided with ahinge 69 to permit the portion above the plane 68 to be swung backwardas shown in Fig. 7, providing access to the mandrel-and-bearingassembly. The reciprocating drive for the link 33 permits this openingof the housing is provided 'with a hinge 69 to permit the fork orgooseneck 5| and the roller 50. The front wall Zia of the housing isprovided With a pivotally mounted latch arm T8 for engaging a flange 1|to normally hold the housing in the closed operating position shown inFig. 2. Also, the bearing 26 for the mandrel is formed in two parts,Figs. 5 and 6, the upper part or cap 26a being hinged on the end wall20c of the base so that it may be swung open to permit removal of themandrel, as shown in Fig. 6. To provide for opening the split bearing 26automatically with swinging of the housing 2| about the hinge 69, thecap 26a has an upwardly extending fork 2Gb coope ating with a pin 2licarried by the end wall 2|c of the housing. When the machine is in theoperative position partly shown in Fig. 5, the bearing cap 26a is rmlyheld closed by the stud 2| f and when the housing 2| is swung backward,as shown in Fig. 6, the cap will also swing upward and backward andleave the bearing open for removal of the mandrel.

To provide for proper axial positioning of the mandrels 24, and toprevent end play, the ends 24h of the mandrels are preferably provided'with grooves 24o, Fig. l, and the separable parts of the bearing 26 areprovided with dog-point screws I2 adapted to extend into the grooves.

After a set of bearing rings 25 on a mandrel 24 has gone through thefinishing operation, the housing 2| may be swung backward about thehinge 69 by first releasing the latch 10, whereupon the mandrel andbearing rings may be removed and another mandrel already prepared withunfinished rings inserted in the machine for iinishing.

Although only ve rings and the reciprocating assemblies for iinishingsame are shown in Fig. 1, it should be understood that a much greaternumber of rings and assemblies may be used in a single machine, and as aresult the productivity of the machine may be quite high since a largenumber of rings may be finished simultaneously in one operation.

Referring to Fig. 2, for the purpose of supplying coolant to the bearingrings 25 at their points of engagement with the finishing elements 35, amanifold pipe 82 is mounted on the inside of the rear wall 2| a of thehou-sing and connected through a pump (not shown) to a suitable coolantreservoir. Also, a second manifold pipe 83 is mounted on the front wall2|a of the housing for the purpose of providing a cleaning solutionwhere this might be desirable, preparatory to subsequent finishingoperations on the bearing rings 25.

A tray 84 is mounted under the mandrel 24 and rings 25, supported bylegs 85, Fig. 2, to receive and carry olf the coolant, or to supplyadditional coolant to the rings when the latter` dip below the level ofthe solution.

As may be understood, wear at the pivot points of the screws 32supporting the holders 3| may be taken up by tightening the screws, andif desired the pivots may be sealed to exclude abrasive grits, etc.

A modified form of holder for the finishing elements is shown in Fig. l2wherein a pair of elements may be brought to bear against each of thebearing rings 25. The holder 'I4 shown in this figure has a pair ofparallel bores slidably carrying sleeves 15 in which are frictionallymounted iinishing elements '.16. To provide for an equalized pressure oneach of the elements 'I6 a ballpointed bridging member 1? is provided,engaging the caps 18 of the sleeves "l5, the member T.' being pivotallyconnected to the extension 19 of the connecting arm 80. According tothis construction, pressure exerted by the bag 5'! on the slide 8| willbe transmitted through the connecting arm and bridging member 11 to bedivided equally between the finishing elements 16.

By the provision of two finishing elements for each bearing race theamount of wear per element is reduced to approximately one-half, andtherefore replacement or readjustment of the elements need not be madeso frequently. Also, the time of finishing of the bearing rings may bereduced. This arrangement is especially advantageous for use with thelarger sized bearing rings, and the elements may be located close toeach other so that they sweep the grooves transversely substantiallyalong their arcs. Also, the finishing elements or stones 16 may have arectangular cross-section equaling together the cross-section ascaoae ofa single finishing element, in which case the contacting surfaces of theelements may more nearly conform to the contour of the grooves at allpoints.

Variations and modifications may be made Within the scope of thisinvention and portions of the improvements may be used without others.

l claim:

l. A machine for linishing grooves in Workpieces, having means forsupporting and simultaneously travelling a plurality of ganged groovedworkpieces; a plurality of holders for carrying and presenting finishingelements to the grooves of the workpieces; and means for simultaneouslymoving each of the holders to cause the finishing elementsto sweep andtraverse the surfaces of the grooves as the workpieces are travelledrelative to the finishing elements.

2. A machine for finishing grooves in workpieces, having means forsupporting and simultaneously travelling a plurality of ganged groovedworkpieces; a plur-ality of holders for carrying and presentingfinishing elements to the grooves of the workpieces; means for movingthe holders to cause the finishing elements to sweep and traverse thesurfaces of the grooves as the Workpieces are travelled relative to thefinishing elements; and means uniting the holders for simultaneous andcorresponding movements.

3. A machine for iinishing grooves in workpieces, having means forsupporting and travelling a plurality of ganged grooved workpieces; aplurality of holders for carrying and presenting finishing elements tothe grooves of the Workpieces; means for moving the holders to cause thefinishing elements to sweep and traverse the surfaces of the grooves asthe Workpieces are travelled relative to the finishing elements; andmeans for yieldingly urging all of the elements against the work withsubstantially uniform and constant pressure.

4. A machine for iinishing concave grooves in workpieoes, having meansfor supporting and rotating a plurality of ganged grooved workpieces;

a plurality of holders for pivotally carrying and presenting nishingelements to the grooves of the workpieces; and means for simultaneouslyswinging the holders to cause the finishing elements to sweep andtraverse the surfaces of the grooves as the Workpieces are rotatedrelative to the nnishing elements.

5. A machine for finishing concave grooves in workpieces, having meansfor supporting and rotating a plurality of ganged grooved workpieces; aplurality of holders for pivotally carrying and presenting finishingelements to the grooves of the workpieces; means for simultaneouslyswinging each of the holders to cause the nishing elements to sweep andtraverse the surfaces of the grooves as the workpieces are rotatedrelative to the finishing elements; and means for simultaneouslyadjusting the pivot points of the holders to accommodate workpieces ofdierent diameters and having different radii of groove curvature.

6. A groove-iinishing machine having a base; a carrier for mounting onthe base a plurality of grooved workpieces in tandem for longitudinalmovement of the grooves thereof; iinishing elements adapted to engagethe grooves of the workpieces; means for mounting the elements on thebaserfcr pivotal movement about the centers of curvature of the groovesof the mounted workpieces respectively so that portions of said elementsmay engage and sweep the grooves transversely, said mounting meanspermitting advancing movement of 'the elements; means for impartingcontinuous movement to the carrier'and mounted workpieces and forsimultaneously reciprocating the finishing elements 'about the saidcenters of curvature; and means carried by the base for applyingsubstantially identical pressures individually to the finishing elementsWhile they are reciprocating, for causing them t0 ad- Vance and bearagainst the grooves of the work pieces for ,finishing the latter.

Y 7. lThe invention as deiined in claim 1 in which the means forapplying pressures to the elements comprises a hydraulic chamber, andindividually operable pressure-transmitting links between the chamberand the elements respectively,

8.- Th'e invention as defined in'claim 1 in which the means for applyingpressures to the elements comprises a hydraulic chamber, andindividually operable two-part pressure-transmitting links between thechamber and the elements respectively, each of said links comprising aslide operatively connected with the chamber, and an arm pivotallyconnected to the slide and the element, and reciprocating with thelatter, the pivotal movement of the arm periodically moving the slide tocause periodic compression of the hydraulic chamber and consequentincrease in pressure applied thereby, and the angularity of the arm withrespect to the slide during such periods of increased pressurefunctioning to reduce the'pres- 'sure transmitted'to the element so thata compensation .is effected to provide for uniformity of pressure on theelement throughout its reciprocation.

9. A groove-finishing machine having a base; a carrier for mounting agrooved workpiece on the base for longitudinal movement of the groovethereof; an elongate nishing element adapted at one end to engage thegroove of the workpiece; a holder carrying the element, pivotallymounted so that the element may swing about a point intermediate itsends whereby the said groove-engaging end may transversely sweep thegroove of the workpiece, said holder permitting advancing movement ofthe element; means for imparting continuous movement to the carrier andmounted workpiece, and for simultaneously reciprocating the holder andiinishing element; a pressure-transmitting link connected at one end toapply pressure to the free'end of the element; a slide mounted on thebase, pivotally connected to the other end of the link to permit thelatter to swing with the holder and element; and an inflatable containermounted on the base, connecting with the slide for applying pressurethereto, said pressure being transmitted through the link to theiinishing element as the latter reciprocates, for causing same toadvance and bear against the groove of the workpiece.

l0. The invention as defined in claim 9, in which there are means forchanging the position of the carrier with respect to the holder so thatthe pivot point lof the latter may be made to coincide with the centersof curvature of the grooves in different-sized workpieces,

ll. A groove-nishing machine having a base; a carrier for mounting onthe base a grooved workpiece; means for demountably mounting the carrieron the base for movement of the workpieces longitudnally ofthe groove ofthe Workpiece carried thereby; a iinishing element adapted to engage thegroove of the workpiece; means for mounting the element for pivotalmovement about the center of curvature of the -groove of the mountedworkpiece so that portions of said element may engage and sweep thegroove transversely, said mounting means permitting advancing movementof the element; means for imparting continuous movement to the carrierand workpiece, and for simultaneously reciprocating the finishingelement about the said center of curvature; means for applying pressureto the finishing element while it is reciprocating, for causing it toadvance and bear against the groove of the workpiece; and means foradjusting the position of the pivot point so that when the workpiece isreplaced in the carrier by a differentsized workpiece the pivot pointmay be made to coincide with the center of curvature of the replacingworkpiece.

12. A groove finishing machine having a base; a carrier for demountablymounting a grooved workpiece on the base for movement of the workpiecelongitudinally of the groove thereof; a housing carried by the base; afinishing element adapted to engage the groove of the workpiece; meansfor mounting the element on the housing for pivotal movement about thecenter of curvature of the groove of the workpiece so that portions ofthe element may engage and transversely sweep said groove, said mountingmeans permitting advancing movement of the element; means for impartingcontinuous movement to the carrier and mounted workpiece, and forsimultaneously reciprocating the element about the said center of thecurvature; means for applying pressure to the finishing element while itis reciprocating, for causing it to advance and bear against the grooveof the workpiece; and means for demountably connecting the base andhousing together whereby the housing may be shifted to separate thefinishing element from the workpiece so that the latter is free forremoval.

13. A groove-finishing machine having a base; a carrier for mounting agrooved workpiece on the base for longitudinal movement of the groovethereof; an elongated finishing element adapted at one end to engage thegroove of the workpiece; a holder carrying the element, pivotallymounted on the base so that the element may swing about a pointintermediate its ends whereby the said groove-engaging end maytransversely sweep the groove of the workpiece, said holder permittingadvancing movement of the element; means for imparting continuousmovement to the carrier and mounted workpiece, and for simultaneouslyreciprocating the holder and finishing element; a pressure-transmittinglink connected at one end to apply pressure to the free end of theelement; a slide mounted on the base, pivotally connected to the otherend of the link to permit the latter to swing with the holder andelement; and yieldable means carried by the base for applying a pressureto the slide, said pressure being transmitted through the link to thefinishing element as the latter reciprocates for causing same to advanceand bear against the groove of the workpiece.

14. A groove-finishing machine having a base; a carrier for mounting onthe base a plurality f grooved workpieces in tandem for longitudinalmovement of the grooves thereof; finishing elements adaptedto engage thegrooves of the workpieces; means for mounting the elements for pivotalmovement about the centers of curvature of the grooves of the mountedworkpieces respectively so that portions of said elements may engage andsweep the grooves transversely, said mounting means permitting advancingmovement of the elements; means for imparting continuous movement to thecarrier and mounted workpieces and for simultaneously reciprocating thefinishing elements about the said centers of curvature; an inflatablecontainer mounted on the base, and fluid conducting means for inflatingsame; and means for transmitting pressure from the bag when inflated tothe finishing elements individually while the latter are reciprocatingforcausing the elements to advance and bear against the grooves ofmounted workpieces for finishing the latter.

15. A groove-finishing machine having a base; a carrier for mounting agrooved workpiece on the base for longitudinal movement of the groovethereof; an elongate finishing element adapted at one end to engage thegroove of the workpiece; a holder carrying the element, pivotallymounted on the base so that the element may swing about a pointintermediate vits ends whereby the said groove-engaging end is adjacentthe workpiece and may transversely sweep the groove thereof, said holderpermitting advancing movement of the element and retracting movement forwithdrawal entirely from the holder; means for imparting continuousmovement to the carrier and mounted workpiece, and for simultaneouslyreciprocating the holder and nishing element; a pressure-transmittinglink demountably connected atv one end to apply pressure to the end ofthe element farthest from the workpiece; a housing carried by the base;a slide mounted on the housing, pivotally connected to the other end ofthe link to carry same and permit it to swing with the holder andelement; an inflatable container mounted on the housing, connecting withthe slide for applying pressure thereto, said pressurebeing transmittedthrough the link te the finishing element as the latter reciprocates,for causing same to bear against the groove of the workpiece; and meansfor demountably connecting the base and housing together whereby thehousing may be shifted from operating position to bodily move the slideand link and separate the latter from the finishing element so that theelement is freefor removal from the holder.

16. The invention as defined in claim 15 in which the connection betweenthe link and iinishing element includes meshing parts carried by saidlink and element, and in which there are means for holding the link,when the housing is shifted from operating position, in a settingcorresponding to a predetermined position of the element, so that thesaid parts may be aligned for meshing when the element is maintained insaid predetermined position and the housing is returned to operatingposition.

17. A groove-finishing machine for ball bearing races, having a base; acarrier for mounting a. plurality of bearing races axially aligned onthe base for simultaneous rotation about their common axis; finishingelements adapted to engage the grooves of the races; means for mountingthe elements for pivotal movement about the centers of curvature of thegrooves of the mounted races Arespectively so that portions of saidelements may engage and sweep the grooves transversely, said mountingmeans permitting advancing movementof the elements; means for rotatingthe carrier and bearing races mounted thereby, and for simultaneouslyreciprocating the finishing elements about the said centers ofcurvature; an inflatable resilient bag mounted on the base, and fluidconducting means for inflating same; and means for transmitting pressurefrom the container when inated to the finishing element individuallywhile the latter are reciprocating, for causing the elements to advanceand bear against the grooves of mounted races for finishing the latter.

18. A groove-finishing machine having a base; means for movably mountingon the base a workpiece for longitudinal movement of the groove thereof;finishing elements adapted to engage the groove of lthe workpiece;aholder carrying a plurality of elements, mounted for pivotal movementabout the center of curvature of the groove of the workpiece so thatportions of said elements may engage and sweep the groove transversely,said holder permitting advancing movement of the elements; means forimparting continuous movement to the carrier and mounted workpiece andfor simultaneously reciprocating the holder and finishing elements aboutthe said pivotal points; and means for applying substantially uniformpressure to the finishing elements while they are reciprocating, forcausing said elements to bear against the groove of the workpiece andfinish same.

19. A groove-finishing machine for ball bearing races, comprising abase; a mandrel rotatably mounted on the base, having means for clampingthereon a plurality of bearing races side by side so that the groovesthereof may be located on predetermined centers; a housing mounted onthe base; finishing elements adapted to engage the grooves of the races;holders carrying the elements, mounted on the housing to pivot aboutcenters respectively in lateral alignment with the predetermined centersof the bearing grooves, said holders permitting advancing movement ofsaid elements; means for rotating the mandrel and clamped races, and forsimultaneously reciprocating the holders to cause portions of theelements to sweep the grooves transversely; means carried by the housingfor applying substantially uniform pressure to the iinishing elementswhile they are reciprocating, for causing them to advance and bearagainst the grooves of the clamped races; and means for adjusting thehousing on the base laterally of the mandrel so that the said pivotalcenters of the holders may be made to coincide with the centers ofcurvature of the grooves of the races clamped on the mandrel, to providefor uniform finishing of the grooves by the said elements.

20. A groove-finishing machine having a base; a carrier for mounting agrooved workpiece on the base for longitudinal movement of the groovethereof; an elongate iinishing element adapted at one end to engage thegroove of the workpiece; a holder carrying the element, pivotallymounted on the base so that the element may swing about a pointintermediate its ends whereby the said groove-engaging end maytransversely sweep the groove of the workpiece, said holder permittingadvancing movement of the element; means for imparting continuousmovement to the carrier and mounted workpiece, and for simultaneouslyreciprocating the holder and finishing element; a pressure-transmittinglink connected at one end to apply pressure to the free end of theelement; a slide mounted on the base, pivotally connected to the otherend of the link to permit the latter `to swing with the holder andelement; and yieldable means carried by the base for applying a pressureto the slide, said pressure being transmitted through the link to thefinishing element as the latter reciprocates for causing same to advanceand bear against the groove of the workpiece, the swinging movement ofthe link periodically moving the slide to cause periodic increases inthe pressure applied thereto by the said yieldable means, and theangularity of the link with respect to the slide during such periods ofincreased pressure functioning to reduce the pressure transmitted to theelement so that a compensation is effected to provide for uniformity ofpressure on the element throughout its reciprocation.

21. A groove-nishing machine having a base; a carrier for demountablymounting a grooved workpiece on the base for longitudinal movement ofthe groove thereof; a housing carried by the base; an elongate finishingelement adapted at one end to engage the groove of the workpiece; aholder carrying the element, pivotally mounted on the housing so thatthe element may swing about a point intermediate its ends whereby thesaid groove-engaging end may transversely sweep the groove of theworkpiece, said holder permitting advancing movement of the element;means for imparting continuous movement to the carrier and mountedworkpiece and for simultaneously reciprocating the holder and finishingelement; a pressure-transmitting link connected at one end to applypressure to the free end of the element; a slide mounted on the housing,pivotally connected to the other end of the link to permit the latter toswing with the holder and element; an inflatable bag mounted on thehousing, connecting with the slide for applying pressure thereto, saidpressure being transmitted through the link to the finishing element asthe latter reciprocates, for causing same to advance and bear againstthe groove of the workpiece; and means for demountably connecting thebase and housing together whereby the housing may be shifted to bodilymove the holder and separate the finishing element from the workpiece sothat the latter is free for removal.

22. A groove-finishing machine having a base; a carrier for mounting agrooved workpiece on the base for longitudinal movement of the groovethereof; a housing mounted on the base; a finishing element adapted toengage the groove of the workpiece; means for mounting the element onthe housing to pivot about an axis parallel to the path of movement ofthe groove of ,the workpiece at at least one point, said mounting meanspermitting advancing movement of the element; means for impartingcontinuous movement to the carrier and mounted workpiece, and forsimultaneously reciprocating the element to cause portions of the latterto sweep the groove of the workpiece transversely; means carried by thehousing for applying a pressure to the finishing element while it isreciprocating, for causing it to advance and bear against the saidgroove; and means for adjusting the housing on the base, including camson one of said parts and a screwoperated cam frame slidable on the otherpart, so that the said pivotal line of the element may be made tocoincide with the center of curvature of the groove of the workpiecemounted in the carriery to provide for uniform finishing of the grooveby the said element.

23. A groove-finishing machine for ball bearing races, having a base; amandrel having means for clamping a bearing race thereon; means fordemountably mounting the mandrel for rotation on the base, including asplit bearing block having a hinged cap; a housing carried by the base;a finishing element adapted to engage the groove of the race; means formounting the element on the housing for pivotal movement about the cen-yter of curvature of the groove of the race so that portions of saidelement may engage and sweep the groove transversely, said mountingmeans permitting advancing movement of the element; means for rotatingthe mandrel and clamped race, and for simultaneously reciprocating thefinishing element about the said center of curvature; means for applyingpressure to the finishing element while it is reciprocating, for causingit 10 to advance and bear against the groove of the clamped race; meansfor hinging the housing on the base whereby the housing may be swung toseparate the nishing element from the bearing race to provide access tothe latter and the mandrel; and a driving connection between the housingand the hinged bearing cap so that when the housing is swung, the capfollows and opens the split bearing, to permit removal of the mandrel.

THOMAS MARREN.

